I have a text substitution setup within the System Preferences. This works most places within OS X as far as I can tell, but it does not work in [Slack](https://slack.com/). (Their native app for OS X version 1.1.4 - 2814)

Does anyone know why?

[![enter image description here][1]][1]

[1]: https://i.sstatic.net/GX1ub.png

**UPDATE**  
It looks like this is not specific to Slack at all